Thread-handling mechanism for sewing machines



May 29, 1934. R, SAIL ER 1,960,924

THREAD HANDLING MECHANISMS FOR SEWING MACHINES Filed March 14. 1933 2Sheets-Sheet 1 I wwweam 3 W @e Rudclph d'scz'ler y 1934- R. J. SAiLER60,924

THREAD HANDLING MECHANISMS FOR SEWING MACHINES Filed March 14, 1933 2Sheets-Sheet 2 Rudd v11 1 sad/er I UNITED STATES PATENT OFFICETHREAD-HANDLING MECHANISM FOR SEWING MACHINES Rudolph J. Sailer,Townley, N. J., assignor to The Singer Manufacturing Company, Elizabeth,N. J., a corporation of New Jersey Application March 14, 1933, SerialNo; 660,609 Claims. (01.112-242) This invention relates to improvementsinsewwork and which supplies also additional slack ing machines and moreparticularly to the threadneedle-thread when the presser-foot is loweredhandling mechanism therefor. preparatory to the first stitch-formingcycle.

One of the objects of this invention is to pro- In the illustratedembodiment my improved vide improved slack-thread producingmechaslack-thread producing mechanism comprises a nism whereby a reservelength of thread is drawn thread pull-01f arm 11 having thread-eyes 11from the thread-supply through the tension when through which theneedle-thread is led. The arm the work is shifted relative to theneedle, the 11 is fixed to one end of a pivot-pin 12 which needle beingthen out of the work and an adis journaled in and extends through thehead 4 ditional reserve length of thread is drawn from of the machineand to the other end of the pivthe thread-supply for the succeedingstitchot-pin is fixed a depending arm 13 formed with forming cycle. aV-shaped cam-portion 14. Fixed to the press- With the above and otherobjects in view, as er-bar 8 by the set-screw 15 is an L-shaped arm willhereinafter appear, the invention comprises 16 to which is fixed by thescrews 17 a wedge- .the devices, combinations, and arrangements ofshaped finger 18 which cooperates with the V- parts hereinafter setforth and illustrated in the shaped portion 14 on the arm 13. Carried bythe, accompanying drawings of a preferred embodi- L-shaped arm 16 is aplunger 19 urged against ment of the invention, from which the severalthe arm 13 by the coiled spring 20.

features of the invention and the advantages The presser-bar 8 is raisedand lowered by attained thereby will be readily understood by the usualfinger-lever 21 having a cam-portion those skilled in the art. 22 whichengages the roller 23 carried by the In the drawings: member 24 which isfixed to the presser-bar. A Figure 1 is a front elevation of a sewingmapin 25 a r y the m m r 24 has piv t d chine of the well known Singertype embodythereto the presser-bar lifting rocker-arm 26 ing the presentimprovements. which is under control of a treadle (not shown).

Figure 2 is a rear elevation of the head of the The above describedraising means for the presssewing machine showing the presentimproveer-bar are old and well known and further dements fixed thereto.scription is deemed unnecessary.

Figure 3 is a left end elevation of the same. From the foregoingdescription it will be ob- The machine shown in the drawings is thatserved that upon raising the Dresser-bar and 8t} type of machine knowncommercially as the presser-foot the wedge-shaped finger 18 engagesSinger 149 Class machine, and comprises the the V-shaped portion 14 ofthe arm 13 and cams usual base 1 from which rises the hollow upthe arm13 to the right as viewed in Figure 2. The right member 2 formed with alaterally overmovement of arm 13 causes the pivot-pin 12 and 1 hangingbracket-arm 3 terminating in a head the slack-producing arm 11 to swingin a clock- 0 4. The head 4 is formed with bearing blocks 5 Wisedirection, as viewed in Figure 1, thereby pulland 5' in which arejournaled the usual pressing a supply of thread through the tensions 28er-bar 8 provided with a presser-device 8' and and 29. The tensions arereleased at this time by reciprocating needle-bar 6 carrying needles '7the usual and well known mechanism, for exam and provided with the usualtension-plate 'I. ple, the tension-releasing mechanism as disclosedLocated below the work-supporting plate 9 are in the United StatesPatent No. 1,410,057, issued the thread-carrying loopers 10 whichcooperate March 21, 1922, to Gatchell. Continued upward with the needlesTin the formation of stitches. movement of the presser-bar causes thewedge- When shifting the work relative to the needles shaped finger 18to ride over the peak of the vit is necessary that a supply ofslack-thread shaped cam-portion 14 thereby permitting the be provided inorder that the material being arm 11 to return to its initial positiondue to presacted upon may be shifted without puckering sure exerted bythe spring-pressed plunger 19.

or gathering the material. After the material Upon lowering thepresser-foot the above dehas been shifted it is necessary that anadditional scribed movements are repeated. From the fore- V supply ofslack-thread be provided to prevent the going it will be obvious thatwhen the presser-foot thread from being broken during the succeeding israised the arm 16 which carries the wedgestitch-forming cycle. To thisend I have proshaped finger 18 is moved to the position shown vided adouble acting slack-producing threadin dotted lines in Figure 2 and.this movement arm which supplies slack needle-thread when the of the arm16 causes the arm 11 to move to the presser-foot is raised preparatoryto shifting the dotted line position shown in Figure 1, and thence 11cback to the full line position, and also when the presser-foot islowered the arm 16 is moved to the full line position shown in Figure 2and this movement of the arm 16 causes the arm 11 to again move to thedotted line position and thence back to the full line position, wherebya reserve length of thread is drawn from the thread-supply when thepresser-ioot is raised and an additional reserve length of thread isdrawn from the thread-supply when the presser-foot is lowered.

Having thus set forth the nature of the invention, what I claim hereinisz- 1. In a sewing machine, in combination, a thread-carrying needle, apresser-bar, means for raising and lowering said presser-bar, and meansunder control of said last named means for pulling a reserve length ofneedle-thread from the thread-supply when the presser-bar is raised andfor pulling an additional reserve length of thread from thethread-supply when the presser-bar is lowered,

2. In a sewing machine, in combination, threadcarrying needles apresser-device movable from operative to inoperative position, andmechanism for supplying slack needle-thread when said presser-device israised to inoperative position and for supplying additional slackneedle-thread when said presser-device is lowered into its operativeposition.

3. In a sewing machine, in combination, a reciprocating needle-bar, athread-carrying needle carried by said needle-bar, a presser-bar, apresser-device carried thereby, means for raising and lowering saidpresser-bar, a thread pull-off lever, and mechanism connecting saidpresserbar with said pull-off lever, said mechanism including means forcausing said pull-off lever to draw a reserve length of needle-threadfrom the thread-supply when the presser-foot is raised and an additionalreserve length of thread from the thread-supply when the presser-foot islow- 5. A sewing machine having, in combination, a

thread-carrying needle, a presser-bar, means for raising and loweringsaid presser-bar, a pivot-pin, a needle-thread pull-off lever carriedthereby, a second lever carried by said pivot-pin and a member carriedby said presser-bar and having means for imparting to said second leveran oscillatory .pin, a needle-thread pull-off lever carried thereby, asecond lever formed with a V-shaped. camportion carried by saidpivot-pin, and amember carried by said presser-bar, said member having awedge-shaped cam cooperating with the V- shaped cam-portion on saidsecond mentioned lever.

'7. The combination as claimed in claim 6 with means for maintainingsaid second mentioned lever in engagement with said wedge-shaped cam.

8. In a sewing machine, in combination, stitchforming mechanismincluding a reciprocating thread-carrying needle and looptaking meanscoordinated therewith, a presser-foot movable in opposite directions toand from work-engaging position, and means influenced by the oppositelydirected movements of the presser-foot for pulling successively reservelengths of needle-thread from the thread supply.

9. In a sewing machine, in combination, a frame, stitch-formingmechanism including a reciprocating thread-carrying needle andlooptaking means coordinated therewith, a member movable in oppositedirections carried by said frame, a thread pull-off element, and meansunder control of said member for causing said thread pull-ofi element topull successively reserve lengths of needle-thread from the threadsupply during the oppositely directed movements of said member.

10. In a sewing machine, in combination, stitch-forming mechanismincluding a reciprocating thread-carrying needle and loop-taking meanscoordinated therewith, a presser-foot movable between work-releasing andwork-engaging positions, and means for pulling a reserve length ofneedle-thread from the thread supply when the presser-foot is moved fromwork-releasing to work-engaging position.

RUDOLPH J. SAILER.

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